The invention is in the field of lamp units, such as screw-in units having a screw base attached to a housing which may contain a ballast, such as a reactor type or an electronic circuit type, connected to a lamp such as a fluorescent type or arc type. The invention is particularly directed to the attachment of the base to the housing.
Various ways have been used, and proposed, for attaching a screw base to a light bulb or to a housing of a lamp unit, such as adhesively cementing or gluing these parts together, or attaching them together with fastening devices such as screws or staples, or by crimping the parts together. For example, U.S. Pat. Nos. 3,953,761--Lo Giudice and 2,421,571--Leyshon disclose cementing a base to a lamp unit with adhesive material, and the latter patent also discloses crimping the base to the lamp unit. U.S. Pat. Nos. 2,817,004--Baumgartner and 4,161,020--Miller disclose the use of screws for attaching a base to a lamp unit, and U.S. Pat. No. 2,525,022--Dupuy discloses a twist-lock attachment of a base to a lamp unit. All of these methods incur an amount of cost for materials and labor.